Students enrolled in graduate programs here at Brock University will be required to submit an electronic copy of their thesis to this repository as part of graduation requirements.

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Once your thesis has been accepted in the Repository you will receive an email confirmation along with a link to your work

Recent Submissions

  • The Experience of Iranian Women Inter-University Athletes with a Focus on Gender in Sport

    Kohandel, Kiana; Applied Health Sciences Program
    This research explores the experiences of Iranian women athletes in inter-university sports, with a particular focus on gender. Utilizing a descriptive, narratively informed approach and the concept of the gender regime, this study aims to provide a comprehensive understanding of the gendered experiences of these athletes. The research addresses two primary questions: (1) What are the lived experiences of Iranian women athletes in inter-university sport? and (2) How do these athletes explore and navigate barriers, supports, and points of resistance in their sporting lives? Semi-structured interviews were conducted with six current women student-athletes from Azad University, and thematic, narrative-informed analysis was used to analyze the data. This method enabled the identification of key themes within and across the participants' stories, highlighting their unique challenges and achievements. The study identified three major themes: Barriers, Norms, and Discrepancies; Resistance, Solidarity, and Support; and Personal Growth and Development. These themes reflect the experiences of Iranian women athletes in university sports, revealing the challenges they face due to inadequate facilities, cultural restrictions, and gender inequality, their acts of defiance and support systems that empower them, and the personal growth that arises from navigating these obstacles. Together, these themes provide a clear picture of the many struggles and successes of women athletes in a sports environment shaped by gender. Despite facing significant barriers, these athletes demonstrate resilience and adaptability, leveraging support networks and personal determination to pursue their athletic goals. The findings emphasize the importance of supportive environments and inclusive policies in promoting gender equity in sports. This research contributes to the broader discourse on gender and sport by providing valuable insights into the specific cultural and contextual factors affecting women athletes in Iran. It underscores the need for further comparative studies in different Muslim-majority countries to explore how varying cultural contexts influence women's experiences in sports. By addressing the unique challenges faced by women athletes in different regions, future research can inform policies and practices that enhance gender equity in sports globally.
  • Examining the effects of implicit and internalized weight bias on physical activity participation for women in larger bodies

    Jabbar, Jesica; Applied Health Sciences Program
    Weight stigma represents discrimination associated with the social beliefs that people in larger bodies have low willpower, are unmotivated, and are personally responsible for their elevated weight. Internalized weight stigma is the extent to which social perceptions of weight stigma are attributed to the self by people in larger bodies. Dual process models may be uniquely situated to help us understand how weight stigma becomes internalized and whether this impacts (physical activity) PA participation. Within dual process models two systems regulate how we think; the associative system reflects automatic associations and feelings, whereas the propositional system represents deliberate and controlled reasoning. Past research has examined social perceptions of explicit weight stigma alongside implicit measures, rather than examining the internalized form of weight bias. The purpose of this study was to examine whether implicit weight bias (an associative process) and internalized weight bias (a propositional process) are significantly associated with the expectation of experiencing weight stigma, self-regulatory efficacy, the tendency to avoid PA, PA intention, and PA. All eligible participants (n = 154) were over 18, self identified as a woman, had a BMI over 25 and self-identified as a person living in a larger body. Implicit weight bias was measured using a single category Implicit Association Test, while the other study variables were measured using validated survey measures. We conducted a series of hierarchical multiple regression analysis, entering covariates in step 1, implicit weight bias in step 2, and internalized weight bias in step 3. In step 3, both implicit and internalized weight bias were significantly associated with self-regulatory efficacy (p <.001, r2 = .183) and light past PA (p < .05, r2 = .065). Contrarily, the expectation of experiencing weight stigma (p <.05, r2 =.120) and the tendency to avoid PA (p <.001, r2 = .297) were both significantly associated with implicit weight bias in step 2. However, once internalised weight bias was added into the equation in step 3, the implicit association became not significant. No relationship was observed between PA intention, implicit weight bias and internalized weight bias. Similarly, there was no relationship observed between moderate to vigorous physical activity, implicit weight bias and internalized weight bias (p > .05). Implicit weight bias and explicitly measured internalized weight bias were associated with psychological cognitions that may deter PA. They seemed to be more strongly related to cognitions than behaviours, which might suggest that they have indirect relationships with PA. Examining both implicit and internalized weight bias together, through a dual process lens provided insight into the nuanced relationship that people in larger bodies have with PA participation. Future health promotion strategies should consider these findings and must work to shift away from their weight centric approach that may exacerbate internalized weight bias and instead, adopt a more weight-neutral approach towards PA participation.
  • Dissecting the role of MAP3Ks TAK1 and ASK1 in IgE-FcERI mediated mast cell exocytosis

    Watson, Colton J. F.; Applied Health Sciences Program
    Mast cells are sentinel immune cells and the main drivers of allergic inflammation. Upon allergen exposure mast cells initiate immediate degranulation in the early-phase of the response, followed by de novo production and secretion of pro-inflammatory mediators in the late-phase. Co-stimulating with allergen and SCF results in the amplification of the pro-inflammatory response launched by allergically-activated mast cells, and a connection between the two signalling pathways is the mitogen activated protein kinase (MAPK) pathway. Therefore, this dissertation includes 3 studies that focussed on MAP3K proteins, TAK1 and ASK1, that are potential nexus points in the signaling mechanisms of the allergic inflammatory response. Our previous work identified TAK1 as a central regulator in co-stimulated mast cells, and study 1 found that TAK1 regulates signaling through both the FcERI and ckit receptor individually as well as supporting that the MAP3K level is an appropriate target for therapeutic development of mast cell stabilizers. Study 2 was carried out to determine if other MAP3Ks, specifically ASK1 also exhibited the regulation observed with TAK1 in allergically-activated mast cells. We found that despite ASK1 sharing the same level in the MAPK cascade, its inhibition did not have as significant an impact in activated mast cells, suggesting that TAK1 is unique in its ability to regulate mast cell function following allergic stimulation. Study 3 was an explorative study to determine how TAK1 is able to exert its regulatory effect on the allergic inflammatory response. We identified a novel interaction between TAK1 and the lipid kinase PIP4K2B. This discovery elucidates the mechanistic placement of TAK1 in mast cells and increases our understanding of the regulation of mast cell inflammatory mechanisms. Taken together, the following research shows that different MAP3Ks exert varying levels of regulatory control in allergically activated mast cells, with TAK1 appearing to be robustly influential, especially compared to ASK1 under the same conditions. Furthermore, we present evidence to support a novel interaction between TAK1 and mechanisms supporting the generation of PIP2, which has the potential to lay the foundation for a new field of study looking into the relationship between the canonical MAPK pathway and lipid metabolism in mast cells.
  • Exploring the Coordination Chemistry of Hydroxy Alkyl Pyridine and Pyrazine Ligands in 3d Cluster Chemistry

    Majidinezhad, Sahar; Department of Chemistry
    Three potentially chiral alkoxide ligands, α-methyl-2-pyridine-methanol (mpmH), dimethyl-2-pyridine-methanol (dmpmH) and methyl-2-pyrazine-methanol (mpzmH), are presented together with select 3d ions for the synthesis and study of three novel polynuclear clusters. The first, a {Ni7} complex prepared from chiral-mpmH, has a unique capped trigonal prismatic topology. Magnetostructural studies reveal that at low temperature it has an S = 0 spin ground state and is not an SMM. The second two complexes are both prepared from rac-dmpmH under the same reaction conditions. Dark green, single crystals, of the kinetic product, a {Ni6} cluster were isolated after 2 weeks. This cluster has a structural topology, comprising four edge-sharing cubanes with missing vertices. Magnetostructual studies reveal the cluster is spin frustrated with an S = 2 ground state at low temperature. AC magnetic susceptibility studies are consistent with field induced SMM properties. After two months, blue plates of a {Ni8} cluster, the thermodynamic product, were obtained. The magnetic core of this cluster has a trapezoidal prismatic topology, containing bridging methyl tetrazolate (mtz−) ligands formed via the in situ, NiII-assisted click reaction between the N3− ions and the MeCN solvent. Reaction of mpzmH with Mn benzoate in the presence of azide ions afforded single crystals of a large mixed valence nanosized {Mn22} cluster which has a pyramidal like structural topology comprised of three layers of Mn4O4 and Mn3O4. DC studies are consistent with the presence of 10 MnII and 12 MnIII ions and the presence of dominant antiferromagnetic interactions at low temperature. AC studies reveal an increase in the in-phase susceptibility (χ′) upon cooling, reaching a broad maximum around 4 K, and the emergence of an out-of-phase component (χ″) below 7 K. However, the sample shows very little frequency dependence to the position of the maximum in χ″. Below 2 K there is the beginnings of an uptick in χ″ suggesting the presence of two distinct relaxation processes. The ac data is complex, and not consistent with the slow relaxation behavior typically observed in polynuclear 3d-SMMs.
  • Physically Active Leisure with (and Beyond) Limits: Exploring the Lived Experiences of Mothers of Autistic Children

    Naamneh Yassin, Halla Jr; Applied Health Sciences Program
    Mothers of autistic children have been shown to be more vulnerable to high levels of stress, poor health outcomes, and reduced engagement in leisure, as compared to fathers of autistic children or to parents of neurotypical children. While research has demonstrated the contribution of physically active leisure (PAL) to supporting well-being, including that of mothers, little is known about the experiences of mothers of autistic children. The purpose of this research was to explore the lived experiences of mothers of autistic children who engage in PAL to understand its meaning in their lives and how these experiences impact their well-being. This was a qualitative study that included 10 mothers (Mage = 39.3 years) who had one or more autistic children (Mage = 9.3 years). Each mother took photographs that reflected her experiences engaging in PAL (e.g., how they engage in PAL, how PAL affects them, and the meaning of these experiences to them), and participated in a one-on-one interview to discuss these photographs and broader experiences of PAL. Data was analyzed using reflexive thematic analysis techniques. Two main themes were developed from the data that collectively capture the lived experiences of participants engaging in PAL. The first theme demonstrates how domestic commitments hinder mothers’ engagement in PAL, and how these are exacerbated by additional challenges related to the specific needs of autistic children (e.g. limited independence, unmet educational and health service needs). The second theme illustrates the ways in which engagement in PAL was empowering for mothers and supported their well-being. Specifically, engaging in PAL helped mothers cope with their life challenges and provided an opportunity for them to confront gender norms associated with womanhood and motherhood, either by resisting or reproducing these norms. This research has implications for informing health and leisure professionals and researchers and providing direction for the development of interventions and strategies for enhancing engagement in PAL for mothers of autistic children and improving their well-being.
  • Emerging Variants and Fading Immunity: Analyzing the Impact in Epidemic Modeling

    Yasmeen, Farhana; Yasmeen, Farhana; Department of Computer Science
    Outbreaks like the recent COVID-19 pandemic underscore the importance of quick and informed responses to control and mitigate the epidemic. This thesis aims to develop a model that can provide deeper insights into how epidemics progress and behave. Accurate epidemic simulation can provide valuable insights into how an epidemic affects the population. This thesis considers both epidemic spread and epidemic severity, and integrates fading immunity into the epidemic model, creating a more realistic representation of real-life scenarios. This research also extends the model by considering diverse population structures in the contact network where different age groups have different levels of immunity strength. An evolutionary algorithm was used to generate and evolve personal contact networks. We analyzed the epidemic dynamics within these networks, focusing on how different proportions of young and old individuals impact the spread and severity of the epidemic. Results reveal that older populations with weaker immunity experience more severe infections, while younger populations with stronger immunity mitigate both spread and severity. The thesis also explores the impact on variant generation, showing that when using the epidemic spread fitness function there is a tendency to produce more variants than when using the epidemic severity fitness function, highlighting the virus's need to mutate in response to existing immunity. When the population is dominated by younger individuals, even though fewer variants are being generated, successful variants tend to exhibit a higher mutation distance to overcome the robust immunity present in the community.
  • Ocean warming, acidification, and chemistry of the South Pacific & North Atlantic: a brachiopod investigation

    Vaez-zadeh Asadi, Nima; Department of Earth Sciences
    Global CO2 emissions drive ocean warming and acidification. Local-level ocean data is limited, so natural archives like brachiopods are used to understand past oceanic conditions. Brachiopod shells record seawater temperatures, chemistry, and acidity. This thesis uses brachiopods from Paterson Inlet, New Zealand (1900–2021), and the Bay of Fundy, Canada (1970–2009) to track past oceanographic conditions and fill local data gaps. Global oceans recorded a decrease in δ13C DIC values of 0.50 ‰ (~1900-1985), comparable to the δ13CB value of -0.48‰ for Paterson Inlet (1900-2014), a rate of -0.04‰ per decade. The Bay of Fundy brachiopods recorded decreasing δ13CB values by 0.25‰ per decade (1970-2009). Ocean acidification is driven by the mixing of atmospheric CO2, and anthropogenic emissions are enriched in 12C, suggesting a link between pH and δ13CB values. The brachiopod shells δ18OB and Li/Ca levels record ambient seawater temperatures. In Paterson Inlet, seawater temperatures calculated with Li/Ca and δ18O values suggest cooling (ΔT = -0.035℃ per decade; 1900-2014). Temperatures calculated with δ18OB values for the Bay of Fundy indicate cooling (-0.25°C per decade; 1970-2009). Bay of Fundy seawater has recorded decreasing δ18OSW values by -0.16 ‰ per decade (1970-2022), reflecting potential arctic meltwater influx, cooling the seawater. The burning of coal drives CO2 emissions. Coal emissions contain various heavy metals, including selenium. Brachiopods record an increase in selenium concentrations of +6.14 mmol (1926-1960). Subsequently, in 1960-1980, selenium content decreased by -7.54 mmol but has since been increasing with a slightly upward trend of +1.78 mmol (2009-2021). Similar trends are observed in the brachiopod’s lanthanum content, another element found in coal, suggesting that brachiopod shell chemistry contains a record of coal burning. Archives such as brachiopods are an important source of information regarding the changing oceans. Although systems exist to monitor oceanic conditions, they cannot trace small-scaled effects. Brachiopods from Paterson Inlet and the Bay of Fundy record local changes in seawater conditions over the past 120 years. Some trends, such as δ13CB values, correspond with global ones, while others, such as temperatures, are not, reflecting the complex interaction of climate and weather/oceanographic changes on a local scale.
  • Reimagining Learning Disabilities: Embracing Difference as an Empowering Resource Amidst Psycho-Emotional Disablism

    Peddigrew, Emma; Department of Child and Youth Studies
    This dissertation explores the experiences of psycho-emotional disablism in individuals with learning disabilities (LDs) and examines how, despite these challenges, they can reframe their LD as a resource. Employing a Critical Disability Studies (CDS) and a social-relational framework, three interconnected studies were conducted. The first study analyzed the public narratives of three prominent LD advocates—Richard Branson, Henry Winkler, and Barbara Corcoran—highlighting how they view their LDs as unique strengths. The second study focused on disability memoirs, revealing both the disabling and empowering experiences of individuals with LDs, highlighting their distinctive strengths. The third study involved qualitative analyses through individual interviews and journal entries with post-secondary LD students, providing a comprehensive understanding of both the challenges and empowering aspects of their lived experiences. These discussions underscore one of the greatest strengths of this dissertation: its ability to integrate positive psychology with disability studies to explore how individuals with LDs, within the broader context of social structures, can navigate psycho-emotional disablism and reconceptualize disability as a resource. The research emphasizes the importance of understanding disability within broader socio-cultural contexts and recognizing the potential for growth, innovation, and success inherent in neurodiversity. It calls for a paradigm shift in education and support systems to promote inclusivity and equity. By highlighting the voices and experiences of individuals with LDs, this dissertation contributes to the broader discourse on disability, empowerment, and self-advocacy, advocating for a more nuanced and strengths-based understanding of LDs. Keywords: learning disabilities, critical disability studies, social-relational, psycho- emotional disablism, strengths-based, resource
  • Intention to use Robo-Advisors, considering the Behavioral Reasoning Theory, and moderating effect of prior knowledge and experience.

    Heidari, Maryam; Faculty of Business Programs
    Robo-advisors, AI-powered financial services, offer personalized investing solutions but have not achieved the expected adoption rates. This study addresses a critical gap in the literature by examining how the value of openness to change influences the intention to use robo-advisors, through the mediating roles of Reasons for and Reasons Against adoption, within the framework of Behavioral Reasoning Theory (BRT). Additionally, the study explores how financial knowledge and investing experience moderate these mediated relationships in a nonlinear fashion. Data collected from 400 participants through a structured survey was analyzed using Structural Equation Modeling (SEM). The results indicate that while personal values indirectly influence adoption intentions, Reasons For significantly enhance, and Reasons Against impede, the intention to use robo-advisors. The nonlinear moderating effects of financial knowledge and investing experience reveal that the influence of these reasons on intention is most pronounced at moderate levels of these moderators but diminishes at low and high levels. Specifically, financial knowledge strengthens the positive impact of Reasons For and mitigates the negative impact of Reasons Against at moderate levels, while investing experience shows a more complex pattern, amplifying and then weakening these effects. These findings underscore the need for targeted strategies that address both the benefits and perceived barriers to robo-advisor adoption, emphasizing the nuanced role of user knowledge and experience in shaping engagement with AI-driven financial technologies.
  • Clinical Periodontal Outcomes and COVID-19

    Rowdon, Larissa Jacqueline; Applied Health Sciences Program
    This thesis research investigated the impact of delays in periodontal maintenance appointments during the COVID-19 pandemic on clinical periodontal outcomes (PD, BOP, PI) in a sample size of 350 patients who either received (n=260) or had never received (n=90) sanative therapy. A hierarchical multiple regression including 3 models was used to evaluate the effect of various predictors on post-pandemic clinical outcomes in both groups for a total of 6 regression analyses. The predictors of interest were a disruption due to COVID-19 (Model 1, 2, and 3), length of delay (Model 2 and 3), pre-COVID-19 clinical measures (Model 2 and 3), sex (Model 3), and smoking status (Model 3). The findings showed that a delay in appointment – regardless of duration – predicted a worsened PD in patients who have received ST (Model 1). Moreover, a longer delay and poorer pre-COVID-19 clinical measures predicted a worsening of all outcomes in patients who have received ST (Model 2). These factors also predicted a greater PI in individuals who have never received ST (Model 2). Smoking status and sex in combination influenced all outcomes for patients who have received ST, wherein current smokers and female sex were linked to a worsening of PD (Model 3). PI was the only clinical outcome significantly affected by smoking status and sex in patients who have never received ST (Model 3). Results of this study suggest that patients who have received sanative therapy to treat periodontal disease are more clinically fragile than patients who have never received sanative therapy. Practically, these findings extend beyond the pandemic, offering insights into patient care strategies for managing disruptions in periodontal maintenance.
  • Investigating Neuromodulatory Mechanisms of Cotransmitter Proctolin in Drosophila Neuromuscular Junction

    Jung, Jae Hwan; Department of Biological Sciences
    Proctolin is a neuropeptide that induces or increases muscle contraction in nearly all arthropods. In the fruit fly, Drosophila melanogaster, proctolin is released onto skeletal muscles as a cotransmitter with the excitatory neurotransmitter, L-glutamate (Glu). This thesis examines mechanisms of action through which proctolin modulates contractions of Drosophila muscles. Chapter 1 includes a literature review of neuromodulation, cotransmitters, neurohormones and effects of proctolin, and it gives a rationale for the scientific questions addressed in subsequent chapters. Previous work showed that increasing neural activity reduces the threshold and EC50 values for proctolin’s ability to increase nerve-evoked contractions. Chapter 2 provides evidence that this activity-dependence cannot be attributed solely to an increase in Glu release with increasing neural activity. Proctolin potentiates contractions elicited by directly applying Glu to larval muscles but does not consistently shift EC50 values. Effects of proctolin and Glu on contraction are supra-additive but do not appear to be synergistic. Chapter 3 demonstrates that proctolin increases calcium-induced fluorescence in muscle cytoplasm by itself and enhances calcium signals elicited by Glu. The effect of proctolin is blocked by nifedipine, an inhibitor of voltage-gated, L-type calcium channels in the plasma membrane, suggesting a role for calcium influx. Proctolin failed to increase calcium-induced fluorescence changes induced by caffeine in calcium-free saline, suggesting that proctolin may not act directly on ryanodine receptors (RyRs) that release calcium from the sarcoplasmic reticulum (SR) into the cytosol. Chapter 4 examines a hypothesis in which activating the proctolin receptor inhibits calmodulin, since calcium-calmodulin complexes are reported to inhibit RyRs at high calcium concentrations, limiting calcium release from the SR. A calmodulin inhibitor, W7, mimicks some but not all effects of proctolin, suggesting that although calmodulin inhibition may contribute to proctolin’s effects, other mechanisms must be involved. Data are presented implicating the possible involvement of protein kinase C (PKC), the cAMP-dependent protein kinase (PKA) and the plasma membrane calcium ATPase (PMCA), which normally removes calcium from the cytosol. This thesis adds to our understanding of how cotransmission of proctolin with Glu modulates muscle performance in Drosophila, and it suggests an experimental framework for investigating effects of cotransmitters generally.
  • Training in Trauma-Informed Positive Behaviour Support for Direct Support Professionals of Adults with Intellectual and Developmental Disabilities

    Bulten, Emily; Center for Applied Disability Studies
    People with disabilities are vulnerable to experiencing trauma due to a complex interaction of systemic and individual factors (McGilvery, 2018), urging for supports that promote safety and control, such as Trauma-Informed Care (TIC) and Positive Behaviour Support (PBS). Behavioural Skills Training (BST) is a competency-based training procedure used to teach a wide selection of professionals work-related skills (Gormley et al., 2019). This study evaluated a multicomponent training package consisting of didactic and activity-based training plus BST implemented with 12 direct support professionals recruited from a community-based organization supporting adults with intellectual and developmental disabilities. A pre-post- follow-up design was used to determine the effectiveness of didactic and activity-based training on knowledge and application of TIC and PBS. BST was used to increase skills related to trauma-informed PBS for a subset of six participants using a multiple probe within-participants single-case experimental design (Ledford & Gast, 2018). The three skills trained were providing opportunities for choice, multiple stimulus without replacement, and paired item preference assessments. Training resulted in increased knowledge and application of PBS and TIC on post- tests and at follow-up. BST was effective in training all skills to mastery, while maintenance and generalization were evident for most skills four to five weeks after training. Implications of the findings, strengths and limitations of the study, and future steps are discussed.
  • An Exploratory Analysis of an Objective Severity Tool to Classify Severe Problem Behaviour

    Stellato; Center for Applied Disability Studies
    This study investigates next steps in the process of tool validation for a Severity Tool designed to objectively classify severe problem behavior. Morgan and Cox (under review) developed a 26-item tool comprised of four sub-domains (frequency, chronicity, intensity, and legal and environmental restrictions) which uses objective data collection strategies to inform item responses. In partnership with the Severe Behavior Lab at the University of Texas San Antonio (UTSA), 47 Texas-based caregivers were recruited to complete the Severity Tool with Brock University researchers while accessing evidence-based services through UTSA. Service provision is delivered through UTSA’s tiered service model. For this study, service components (including hours of service received and intervention approach) were summarized along with study sample descriptive characteristics, and Severity Tool subdomain patterns. I examined the association between raw Severity Tool scores and intervention approach applied (function-based vs non-function based) to achieve 80% reduction of behaviour from baseline. Fifty-six percent of the sample were prescribed non-function based interventions, while 44% saw effective behaviour reduction with a function-based approach. Severity Tool raw scores were lower for participants who experienced function-based interventions (M = 8.50). Following this, I enacted a likelihood analysis to support a receiver operating characteristic (ROC) curve. Although underpowered, preliminary findings suggest that the Severity Tool may have utility, but further validation is required to confirm its reliability and clinical applicability.
  • GNN-based Handover Management in 5G Vehicular Networks

    Mehregan, Nazanin; Department of Computer Science
    The rapid advancement of 5G technology has transformed vehicular networks, delivering high bandwidth, low latency, and faster data rates for real-time applications in smart vehicles and smart cities. This enhances traffic safety and the quality of entertainment services. However, challenges remain, such as 5G's limited coverage range, which requires the installation of additional base stations, and frequent handovers, known as the "ping-pong effect," that can cause network instability, especially in high-mobility environments. Traditional reactive methods struggle to manage these issues effectively. In this study, we propose TH-GCN (Throughput-oriented Graph Convolutional Network), which optimizes handover management in dense 5G environments using graph neural networks (GNNs). TH-GCN predicts optimal connections and the best handover choices by modeling vehicles and towers as nodes in a dynamic graph, with connections depicted as edges and incorporating features like signal quality, vehicle mobility, throughput, and tower load. By shifting from a purely user-centric to a combined user equipment and base station-centric approach, our method provides a comprehensive view of the network and enhances adaptability in real-time handover decisions. After conducting several batch tests in our Simu5G simulator, the results showed significant improvements, including up to a 78% reduction in handovers and a 10% improvement in signal quality compared to state-of-the-art methods. TH-GCN effectively reduced handovers while maintaining optimal levels of throughput and latency, particularly in high-density, high-mobility scenarios.
  • What Would it Take for You to Stop Driving to Work? Employer-Based Transportation Demand Management at Brock University

    Fournier, Paige; Department of Geography
    The prevalence of automobile dependency is a long-standing barrier to achieving a more sustainable future. To overcome it, cooperation between the private, public, and individual sectors is needed. The public sector has historically been the main agent of change in this capacity, and the role of the private sector is underrepresented even though employers have the potential to implement policies that can effect change. One sway is through the implementation of employer-based transportation demand management (TDM), which is a set of policies that can be used to influence the commute behaviors of employees. From the employees at Brock University, in St. Catharines, Ontario, we wanted to know: What would it take for you to stop driving to work? To this end, our research questions include: ‘How do Brock employees currently travel to and from work?’; ‘Which TDM policies would most and least likely encourage employees to consider using sustainable modes of transportation for their commute, if they do not do so already?’; and ‘What are the implications of this research for employer-based TDM strategies at Brock University and beyond?’ To answer these questions, we employed the use of an online stated preference survey, distributed over email and through campus-wide posters. Our results show that most of Brock's employees rely on their automobiles, and they may not yet be willing to give them up. However, they could be convinced to carpool and participate in mode-switch days, or to adopt more sustainable transportation habits with the help of shift flexibility. Most of all, we have shown that there is a possibility to enact policies that could effect change, even in an automobile dependent landscape.
  • Teaching Community Service Providers to Support Caregiver PECS Use: An Evaluation of the PECSperts Facilitator Training Model

    Gay, Elizabeth; Center for Applied Disability Studies
    Research examining how to train facilitators to implement the Picture Exchange Communication System (PECS) with caregivers and children is scarce. This research gap presents a barrier to offering PECS as a community service. Currently, there is some empirical research supporting the effectiveness of behaviour skills training (BST) and pyramidal training to train facilitators to implement behavioural interventions. Building on this foundation, the present study used a quasi-experimental, non-randomized group design to explore the effectiveness of a manualized BST training model (i.e., the PECSperts Facilitator Training Package) within a pyramidal training approach. Sixteen community facilitators participated in the study. Participants who immediately received training demonstrated a significant increase in treatment integrity from pre- to post-training assessments. These results maintained during the five week follow up period and generalized to the participants’ clinical practice with families in the community. Participants who did not immediately receive training, did not demonstrate an increase in treatment integrity from pre- to post-training assessments. Later, the training procedures were replicated with the participants who did not initially receive training. After participation in the PECSperts Facilitator Training, these participants’ treatment integrity scores also significantly increased. Participants rated the training positively on a social validity questionnaire. The results provide preliminary evidence for the use of the PECSperts Facilitator Training as an effective training model for training facilitators to teach caregivers to implement PECS with their autistic children. Results of this study have implications for increasing community capacity and access to facilitator PECS training.
  • Examination of voluntary wheel running on markers of adipose thermogenesis in intact and ovariectomized female mice

    Sweezey-Munroe, Jacob; Applied Health Sciences Program
    Estrogen plays an important role in adipose tissue (AT) metabolism. Post-menopausal estrogen loss leads to increased abdominal fat and worsened metabolic outcomes. Exercise, known to enhance energy expenditure and promote AT browning, may offer therapeutic potential to mitigate these adverse effects, particularly through the modulation of brain-derived neurotrophic factor (BDNF) and uncoupling protein-1 (UCP1) in adipose tissue. This study aimed to investigate the effect of voluntary wheel running (VWR) in ovariectomized (OVX) mice on whole body energy expenditure and body composition, key protein markers of thermogenesis and adipose tissue browning, and fluctuations in circulating and AT BDNF and receptor content. It was hypothesized VWR would either prevent or mitigate increases in adiposity due to OVX, enhance thermogenesis and AT browning in WAT depots, and elevate BDNF levels in both circulation and AT. A total of forty C57BL/6J female mice (24 weeks of age) were utilized for this study, twenty of which were subjected to bilateral ovariectomy (OVX=20) while the remaining twenty underwent a sham surgery (SHAM=20). SHAM and OVX mice were further randomized into one of two experimental groups: 1) sedentary (SHAM SED=10, OVX SED=10) and 2) voluntary wheel running (SHAM VWR=10, OVX VWR=10) for the duration of the study period (8-weeks). OVX mice gained more weight over the course of the 8-week study when compared to SHAM mice (P=0.0008). Serum BDNF was higher in mice with VWR access (P=0.0004). Final week lean body mass of VWR groups was trending (P=0.0641), with higher lean mass compared to SED groups. Key tissue specific protein markers responded in a depot-specific manner; notably, TH which was consistently lower in all depots in response to OVX, yet only higher in response to VWR in gWAT (P=0.040). Additionally, VWR groups also had higher ERα (P=0.045) and ERβ (P=0.008) protein content in the gWAT and iWAT depot respectively. This study demonstrates that estrogen deficiency with ovariectomy disrupts adipose tissue function and overall metabolism, while voluntary wheel running can mitigate some of these effects, emphasizing the importance of exercise in maintaining adipose tissue functionality and health in post-menopausal women.
  • The Fear Enjoyment Hypothesis: Psychopathic Traits and Invincibility

    Csordas, Amy; Department of Psychology
    The main objective of this study was to examine whether invincibility mediates the relationship between psychopathic traits and fear enjoyment. Brock University undergraduate student participants (N = 81) viewed either a neutral video or a video intended to decrease feelings of invincibility and then played a horror game in Virtual Reality. Participants rated the videogame on a list of adjectives which captured fear and exciting affective appraisals. As expected, psychopathic traits were associated with lower fear scores and higher excitement scores. The video condition was not a significant predictor of mediation in the initial model. However, in the control condition the relationship between psychopathy and fear enjoyment was replicated, when each condition was examined separately. More specifically, psychopathic traits were related to a less negative and more positive perception of their emotional state. When participants’ feelings of invincibility were manipulated, this relationship was no longer significant suggesting that feelings of invincibility may be important in being able to enjoy fear-inducing stimuli. These findings align with the Fear Enjoyment Hypothesis (FEH). Future research could investigate invincibility as a mediator with a larger sample size.
  • Federated Learning on Knowledge Graphs via Contrastive Alignment

    Mahmud, Antor; Department of Computer Science
    In traditional federated learning (FL) frameworks for knowledge graph embeddings (KGE), individual clients train their local KGE models independently, and a central server collects and aggregates (e.g., by averaging) these models to produce a global one. This process ensures data privacy throughout the FL training process, as the server does not require direct access to clients’ data. However, the performance of traditional FL global aggregation algorithms is significantly challenged by the non-identical distribution of data across clients’ knowledge graphs. To tackle this issue, we introduce AlignNet, a novel supervised contrastive learning (CL) approach that helps align both entity and relation embeddings across clients in federated settings. AlignNet works by pulling similar embeddings closer together while pushing dissimilar ones further apart, using only the existence of entities and relations without accessing the underlying data or detailed associations. This alignment process ensures robustness and better generalization across diverse clients, while still maintaining privacy. Our experiments on benchmark datasets, show that AlignNet consistently outperforms current FL methods, especially with more complex models and datasets. We found that AlignNet effectively reduces the variability and noise introduced by the FL process. While traditional FL setups tend to lose performance as more clients join the aggregation process, AlignNet improves as the number of clients increases. This makes AlignNet a strong choice for large-scale federated settings with many clients and diverse data. Overall, our results show that AlignNet is a scalable and reliable solution for federated KGE, making it an excellent fit for real-world applications like healthcare, finance, and distributed IoT networks, where handling data diversity and maintaining performance at scale are crucial.
  • Insect-specific viruses: infection rates and routes of transmission in Aedes aegypti mosquitoes

    El Khal, Assmaa; Centre for Biotechnology
    Insect-specific viruses (ISVs) are viruses that are described to only infect and replicate in insect cells. Viruses such as cell fusing agent virus (CFAV), Phasi Charoen-like virus (PCLV) and Negev virus (NEGV) are ISVs that are often found in wild mosquitoes and have been shown to suppress the replication and transmission of arthropod-borne viruses (arboviruses), like dengue, chikungunya, and Zika viruses. In particular, it has been shown that wild-type and modified negeviruses can suppress, in vitro, the replication of chikungunya virus and Venezuelan equine encephalitis virus. ISVs have been indicated as a potential biological tool for pathogen control because of this ability to inhibit the replication of arboviruses. To be able to use ISVs to decrease the spread of arboviruses, their routes of transmission and infection rates among insects need to be understood. In this thesis, experiments were used to determine if mosquitoes could be infected with ISVs during their larval aquatic life stage and during their adult life stage. The larval stage of Aedes aegypti mosquitoes, a major vector of arboviruses, was exposed to cell cultures co-infected with CFAV, PCLV and NEGV, as well as to cell cultures infected with NEGV alone. Our results indicate that NEGV can be horizontally transmitted to the mosquitoes during their aquatic stage of development during coinfections with other ISVs and when alone. Next adult mosquitoes were exposed to NEGV through sugar meals that were spiked with NEGV. This method also resulted in successful infection, which was followed by the confirmation of vertical transmission, from the infected parents to their offspring, as well. These experiments revealed desirable characteristics for ISVs that can be used as biological control agents and makes NEGV a potential candidate to combat mosquito- borne pathogens.

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